There has heretofore been employed a static image pick-up device. of the type that produces three color image signals by means of red (hereinafter identified simply by R), green (hereinafter identified simply by G) and blue (hereinafter identified simply by B) color filters provided in a single-plate or single-tube image pick-up device. Such a static image pick-up device performs pixel interpolation processing through the use of adjacent pixel signals so as to obtain three color signals for each pixel. In the pixel interpolation processing, data is easier to process as a digital signal, but digitization of image signals as they are will involve an enormous amount of information; hence, it is customary to carry out signal compression through utilization of the redundancy of video signals with a view to saving the storage capacity of a coded image memory for recording image signals and the signal transmission time. Since it is effective in the pixel interpolation to process the three color signals of different characteristics individually according to color, the signal compression is conventionally performed using a coding circuit provided for each color, that is, using coding circuits of three lines.
By the way, such a static image pick-up device involves complex processing for signal compression and has shortcomings of prolonged computing time and increased power consumption accordingly. To solve these problems, a static image pick-up device disclosed in Japanese Pat. Appln. Laid-Open Gazette No. 4-170886 adopts a method which carries out signal compression by a coding circuit of one line after extracting the color image signals for each color.
FIG. 18 is a diagram depicting a color signal extracting method of the static image pick-up device disclosed in the above-mentioned Japanese Pat. Appln. Laid-Open Gazette No. 4-170886. In FIG. 18, reference numeral 20 denotes an imaging device covered all over the surface thereof with strip-like color filters of three colors; 21a denotes an R component derived from the output signal of the imaging device 20; 21b denotes a G component derived from the output signal of the imaging device 20; and 21c denotes a B component derived from the output signal of the imaging device 20.
The static image pick-up device disclosed in Japanese Pat. Laid-Open Gazette No. 4-170886 extracts output signals of the respective color components R, G and B individually from the imaging device 20, then converts them into digital signals, and sequentially compresses the digital signals by a coding circuit of one line, thereafter recording them on a floppy disk, IC card or similar coded image memory for each color.
In the static image pick-up device disclosed in Japanese Pat. Laid-Open Gazette No. 4-170886 with such a construction as described above, it is necessary to read out the image signals directly from the imaging device for each color--this requires the provision of a dedicated imaging device from which image signals can be read out directly for each color and dedicated hardware therefor.
Since only one line of coding circuit suffices for the traditional static image pick-up device, its construction is simplified accordingly; however, the coded image memory needs to store all color signal components of one frame, and hence it is required to have a large storage capacity.
When the static image pick-up device is formed using an image processor, the amount of data that can be stored in the coded image memory is limited, so that large amounts of data cannot be processed in succession--this gives rise to a problem that high-speed continuous shooting is impossible.
Furthermore, when the static image pick-up device is formed using the image processor, no high definition reproduced images can be created because of limitations on the reduction of the area of one pixel of an imaging device using a CCD (Charge Coupled Device) or the like.
Moreover, when the static image pick-up device is formed using the image processor, it necessarily takes a certain amount of time to display reproduced pictures because coding and decoding of image signals consume predetermined amounts of time.
The present invention is intended to solve such problems as mentioned above and to provide a static image pick-up device which enables color image signals to be read out for each color through the use of an ordinary imaging device.
Another object of the present invention is to provide an image processor and an image processing method which can be realized using only one line of coding circuit and a small capacity coded image memory.
Another object of the present invention is to provide a static image pick-up device which permits high-speed continuous shooting.
Another object of the present invention is to provide a static image pick-up device which creates high definition reproduced images.
Still another object of the present invention is to provide a static image pick-up device which produces a high-speed display of reproduced pictures.